Admission as a nonimmigrant is evidenced in most cases by the immigration officer annotating the nonimmigrant's Form I-94 with the date and class of admission, and the expiration date of the period of authorized stay.
The DHS stamp and notations on Form I-94 show the nonimmigrant's classification, the place and date of the person's admission to the United States, and the period of stay authorized. When an individual needs to demonstrate his or her current nonimmigrant category when applying for a benefit, Form I-94 is always included as part of proof of status.
The I-94 also serves as the principal "registration document" that an International student is required to keep on his or her person.
If the inspecting officer at the port of entry has made an error on Form I-94, it is important to get that error corrected promptly. Errors made by CBP officials at a port of entry should be corrected by CBP, and the alien can get this done by reporting to the nearest deferred inspection office or port of entry, even though that might not be where the alien originally entered the United States. Practices vary from one location to another, and the alien should make sure to contact the office before arriving.